Circular unit heater



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Feb 27, 1945- w. J. HARTWIG a CIRCULAR UNIT HEATER Filed Dec. 26, 1942 3Sheets-Shee't 3 'Patented ret. 27, 1.945 7 CIRCULAR UNIT HEATER WalterJ. Hartwig, Wausau, Wis., assignor to- D. J. Murray Manufacturing acorporation of Wisconsin Co., Wausau, Wis.,

Application December 26, 1942, Serial No. 470,157

" roxanne. 101.2574137) The present invention relates generally toimprovements in the art of conditioning and distributing air or othergases, and relates more especially to various improvements in theconstruction and operation of circular heat transfer devices of the typehaving one or more heat transfercoils and an air circulating fan orblower embodied in a single unit which is adapted for installationdirectlywithin or closely adjoining the space in which the air is to b'econditioned.,

The principal object of this invention is to -provide a new and usefulunit heater or cooler which is simple and compact in construction,

' vortex lbreakers,'diilusers and airv distributors of different types,and having a moto-r driven air circulating fan the propelling mo-tor ofwhich is amply ventilated and protected against excessive heat a-t alltimes.

To provide an improved unit heater assemblage which occupies minimumspace, which is highly attractive in appearance, and which can and whichis also highly efficient in operationv and extremely exible in itsadaptations.

Sonie of the more important specific objects of the present inventionare as follows:

To provide an improved air conditioner having one or more approximatelycircular .heat transfer coils each provided with a multiplicity of heatradiating fins, and which may be readily assembled for most effectivecooperation with an air circulating fan; or blower.

YTo provide an improved heat transfer assem blage for heating orcoo-ling a continuous stream of air or other gas, which is adapted tomost effectively distributethe treated gas ,throughout the Zone ofutilization thereof.

To provide an improved unit heater comprising annular heat transferelements and an air Vcirculating fan ooperating therewith, which is welladapted for overhead suspension with its central axis'disposed eithervertically, or horizontally, or in any intermediate angular position.

To provide a heating unit having one or more annular heat transfer coilsprovided with, inwardly directed hea't radiating ns formed toproduce-enlarged air 'entrance area and to thereby minimize the entrylosses.

To provide a most ,eflicient, compact and durable unit heater especiallyadapted forv downblow distribution of heated air, and havinginterchangeably similar heat transfer coils which ymay be readilyassembled in different numbers so as to produce units of greater orlesser capacities.

To provide a heating assembly lcomprising relatively fewsimple'partsjvhich may be readily constructed and convenientlyassembled, and in which the direction of flow of theair and of theheating medium through the unit maybe reversed withoutmaterially'affecting the Operating eilicieiicy of the assembly.- l

To provide an improved heat transfer struc.-

ture adapted to interchangeably cooperate with be manufactured vand soldat moderate cost for diverse uses.

These and other specic objects and advantages will be apparent from thesubsequent description.

A clear conception ofthe various features constituting the presentimprovement, and of the construction and operation of a unit heaterembodying the invention, may be had `by referring` to the drawingsaccompanying and forming a part of this specification wherein likereference characters designate 'the same or similar parts in the variousviews.

Fig. 1 is a side elevation of a vertically disposed down-below unitheater built in accordance with .this invention;

Fig. 2 is a bottom view of the vertical unit heater of Fig. 1; v

Fig. 3 is a rather irregular vertical section llrough the down-belowunit heater, taken along the lines 3-3 of Fig. 4;,

Fig. 4 is a transverse horizontal section through the unit heater takenalong the line 4 4 of Fig. 3;

Fig. 5 is a side elvation of a 'horizontally disposed similar unitheater; and

Fig. 6 is a front view of the horizontally disposed unit heater.

While the invention has been shown and described herein Ias beingespecially applicable to circular unit heaters each embodying a seriesof annular finned heat transfer coils and a motor driven fan cooperatingtherewith, it is to be understood that it is" not my desire or intent tounnecessarily restrict the scope orthe utility ofA the improvement byvirtue of this specific embodiment, since some of the improved featuresmay also be advantageously applied to coolers for air o r other gases.

Referring to the drawings, the improved circular heat transfer unitcomprises in general several concentric annular heating sections orcoils 8 of interchangeably similar construction each having an internalcontinuous chamber. 9 forv Vheating medium, and a multiplicity ofexternal radiating fins I Il, I I directed inwardly toward the center ofthe annulus; opposite side sheets l2, I3

' or pipe plugs, and some .f The radiating fins l0,

. the unit.

adjacent to thebosses 20,' vpermit'free circulation of the air aboutthese I0, II are so formed and Adisposed that they able by' means of anelectric motor i6 mounted or" .the side sheetwithin a central depressionI1 i2 to produce @a continuous circulation of air through the passageI4; and a vortex breaker or diffuser IS detachably secured to thetubular outthe heating sections; a rotary let portion lil of the otherside sheet I3, coaxially i of the fan i5 and motor I5.

The improved annular heat transfer sections or coils 8 with the iinsIll, iI formed integral therewith, may be readily constructed byordinary foundry methods, and each of these coils 8 is provided with aseries of integral bosses 25, 2i which are tapped for the reception ofpiping, nipples, oi which are adapted to coact with the correspondingbosses of adjacent coils. As shown, there are three similar annular coilsections 8 in the assemblage, but depending upon the heating capacityrequired, any desired number of coils` 8 may be provided. These coilsections 8 are stacked or superimposed, one upon another, and are firmlyinterconnected by means of two sets of diametrically opposite specialnipples 22 which coact with the adjoining larger bosses 2Ily of theadjacent tubular coils, and these hollow nipples 22 also serve toprovide open passages connecting the several chambers 9, see Fig. 3. Oneof the outer bosses is connected to a heating medium supply pipe 23,while the outer boss 2 0 on the opposite side of the coil assemblage andon the opposite side of the central axis, is connected to an exhaustpipe 24, as illustrated in Fig. 1, and the two remaining outer bosses 20are closed by pipe plugs 25. The supply and exhaust pipes 23, 24 maycommunicate with either side of the unit, posed vertically, at the topwhile tom.` All of the smaller innerbosses 2I are normally sealed bymeans of standard pipe plugs 26, but the outer-most bosses 2| areprovided with special plugs 21 having threaded outer ends projectingthrough openings in the casing sheets I2, I3 and with which clampingbolts or nuts 28 coact. These special plugs 21 and nuts 28 cooperatewith the special nipples 22 to retain the casing and coils firmlyassembled, without necessitating the provision of additional clampingbolts.

II which are formed integral with the coil bodies, are all directedinwardly toward the central axis of the unit heater, and these finscooperate with the casing sheets I2, I3to form passageways constitutinga part of the passage I4 for conducting the airthrough The longer finsI0 are arranged in groups and the fins I0 f each group are disposedapproximately parallel to each other, although they are in factseparated somewhat farther apart at their outer ends than at the innerends thereof, in order to permit free entry of the incoming air and toreduce entry losses to a minimum. The shorter iins II arev likewisearranged in groups 2I and are formed to the supply pipe 23 is preferablybosses; and al1 of the fins will provide maximum radiating surfacewithout undesirably obstructing the free iiow of air through theassemblage, and

tical unit heater, comprises but when the assemblage is disthe exhaustpipe is at the botf of vanes or louvers .and toward the fan yripheraisuspension lugs 34 y ,l shown in Figs. -5 and 6 may that they may alsobe readily cast integral with the coils.

While the heat transfer coils 8 are preferably produced by casting, theopposite side sheets I2, I3 of the casing may eitherbe cast or formed ofsheet metal and by welding parts together. The central conical portionor depression I1 of the side sheet I2, is adapted to change thedirection of the flow of air passing through the unit, from radial toaxial, and has a central opening 29 at its smaller end directed awayfrom the motor i6 I5. The depression I1 may also be provided withbrackets 30 for supporting the fan motor Iii, and the fan rotor I5 mayeither be removably attached to the motor shaft 3| by means of bolts 32,or the motor IB may be reversible in operation, so that the ian actionmay be reversed. The casing sheet the tubular portion I9 forming a duet33 within which the fan rotor I5 is rotatable, and both of the housingsheets I2, I3 are provided with pewith which vertical suspension rods 35may be caused to cooperate as shown in Figs. l and 2, when the unit isdisposed vertically.

The vortex breaker or diffuser I8 for the veran outer ring which isdetachably secured to the tubular portion I9 of the casing sheet I3 bymeans of bolts or screws 36, a flaring central tube 31 disposedcoaxially of the opening 29 and fan I5, and a series of radial vanes 38connecting the outer ring with the tube 31 so as to prevent excessiveswirling of the heated air delivered from the unit. While the diffuserI8 is shown as being metal, it may be built up of sheet metal and thevanes 38 may be made adjustable.

While the diffuser ISand the mode of suspension, is suitable forcooperation with most vertically disposed unit heaters of the improvedtype, it may also be desirable to suspend the unit from above with itsaxis horizontal, and to provide for changing the direction of the streamof heated air delivered from the unit heater. In such cases a suspensionrig and diffuser such as be provided, and the unit heater assemblyremains unaltered except for these two parts. Y

The substitute suspension rig of Figs. 5 and 6 consists of a pair ofthrough bolts 40 coacting with the ears 34 formed on the side plates I2,I3, and a U-shaped clamping member 4I embracing each of the bolts 40 andbeing adjustably attached to the lower ends of the adjacent suspensionrods 42 by means of clampingbolts 43. As shown, the unit heater issuspended with its central axis horizontally disposed, but by releasingthe bolts 4I, this unit may be tilted in either direction so that itscentral axis will assume an oblique angle or even a vertical position.quently be tightened to unit in the desired position of adjustment.

The substitute diffuser 44 of Figs. 5 and 6 consists of an outer ringadapted for attachment to the tubular portion I9 of the casing plate orsheet I3 by means ofthe screws 3 6 and having a series 45 pivotaliysuspended therein by means of friction pins 4l. The louvers 4l may beindependently adjusted to any desired position so as to direct the warmair in the desired direction, and also serve as vortex breakers ordiffusers for the hot air stream leavingthe heater.

During normal operation of the improved unit heater assemblage, theannular chambers l o! thefinned coils 8 should be constantly supplied I3is provided with' formed of one piece of castl The bolts'43 maysubsefirmly retalnthe heating e iciI of its contact with the -heatedfins. The direc- Y but also facilitates construction and assembly of theimproved unit heaters, and the fan. I5 and its driving motor are bothamply protected against damage by impact and heat. The improved heaterassemblage obviously occupies very little space, has no unsightlyprojections, can be conveniently suspended from above and in any angularposition, and can be manufactured and sold at moderate cost.

It should be understood that it is not desired to limit this inventionto the exact details of construction or to the precise mode ofoperation, herein shown and described, for various modications withinthe scope of the appended claims,`

may occur to persons skilled in the-art. l

I claim: 1. In combination, several similar annular coils concentricallystacked and each having diametriwill effect uniform distribution of theheated air.

In this mannery the improved unit heater will continuously andeiectively heat the air stream, and will deliver a uniformly heated ilowof air to the space which is to be heated. y

The improved unit is extremely simple and compact in construction andflexible in its adaptations, by virtue of the fact that either pipe 23,2| may be used as an inlet for heating medium, the direction of iiow ofthe air stream may be reversed either by reversing the motor or the fan,

the diffusers I8, may be interchanged, and the overhead' suspensions maybe interchanged. While the suspension rig of Figs. l and 2 is simple andsuitable for vertical suspension of the unit, the rig of Figs.` 5 and 6will permit varied disposition of the heater; and the formation anddisposition of the radiating iins I0, II improves the eiliciency byminimizing the air entrance losses and shock, and also preventsoverheating of the motor I6 when the unit is idle.

' From the foregoing detailed description it will be apparent that mypresent invention provides a highly` useful unit heater which is simple,durable, and compact in construction, and which cally opposite bossescoacting with corresponding bosses of the adjacent sections and allprovided with alined threaded openings, hollow nipples rigidlyconnecting said coils at said openings, inlet and exhaust pipesconnected to said coils at some of said openings, a casing coacting withsaid coils to provide an air passage therethrough, and attaching meansfor said casing providing closures for some of said threaded openings.

2. In combination, several similar coils each having alined bosses onthe' opposite sides thereof provided with threaded openings, hollownipples connecting the adjoining openings of the adjacent coils, pipeplugs closing other of said openings, a casing coacting with said coilsto provide an air passage surrounding the latter, and attachingmeans'for said casing secured to some of said plugs.

is moreover eicient in operation and very flexible in its adaptations.While the assemblage is especially adapted for heating' air, it may alsobe advantageously used for cooling purposes, and the circular or`annular heat transfer coils can be readily manufactured and assembled ingroups of any desired number. The formation and dispositionA of theradiating-fins on the Sections or coils l, not only augments theoperating ,emciencm 3. In combination, several similar concentricannular coils each having alined bosses on the opposite sides thereofprovided with threaded openings, hollow nipples connecting the adjoiningopenings or the adjacent coils, a casing coacting with said coils toprovide an air passage within which said coils are disposed, and commonmeans for attaching said casing to said Acoils and for sealing some ofsaid threadedopenings.

4. In combination, several similar .concentric annular coils each havingalined bosses on the opposite sides thereof provided with threadedopenings, hollow nipples connecting the adjoining openings of theadjacent coils, a casing coacting with said coils to provide an airpassage within which said coils are disposed, and pipe plugs clossomeoi' said openings and having said casing detachably secured thereto.

WALTER J. HARTWIG.

